GB790016A - Improvements in or relating to the production of animal growth stimulants - Google Patents

Abstract

A growth stimulating substance for animals is obtained by contacting a streptomycin fermentation broth with a carboxylic acid ion exchange resin to remove streptomycin and concentrating the streptomycin-depleted liquid. The product may be mixed with calcium carbonate, fuller's earth, flour or meal, whey or dried skim milk, or with the material obtained on drying a presscake of mycelium and filter aid from a penicillin, oxytetracycline, chlortetracycline or tetracycline production. The product may be added in a proportion of 0,5-1 per cent to a nutritionally-balanced feed, e.g., a poultry feed containing 50-80 per cent of grain, 3-10 per cent of animal and 5-30 per cent of vegetable proteins, 2-4 per cent of minerals, and vitamin supplements. According to examples, acidified, filtered streptomycin broths are adjusted to pH 7,0, streptomycin is removed by passage through a column of the resin, e.g. that obtained by copolymerizing methacrylic acid with a small proportion of divinylbenzene, the effluents are concentrated by evaporation at 50 DEG C. under reduced pressure, the concentrates are drum dried, and the dry products are mixed with a dry penicillin presscake and a dry mixture of oxytetracycline and penicillin presscakes; according to a further example, vitamin B12 is adsorbed from the effluent before it is concentrated and dried, the effluent being adjusted to pH 2,5, fuller's earth added, the earth filtered off, and the filtrate adjusted to pH 6,5.